export function addClass(el, className) {
  console.log(hasClass(el, className))
  if (hasClass(el, className)) {
    return
  }
  let newClass = el.className.split(' ')
  newClass.push(className)
  el.className = newClass.join(' ')
}

export function hasClass(el, className) {
  let reg = new RegExp('(^|\\s)' + className + '(\\s|$)')
  return reg.test(el.className)
}

export function getData(el, name, val) {
  const prefix = 'data-'
  name = prefix + name
  if (val) {
    return el.setAttribute(name, val)
  } else {
    return el.getAttribute(name)
  }
}

let elementStyle = document.createElement('div').elementStyle

let vendor = (()=>{
  let transformNames={
    webkit : 'webkitTransform',
    Moz:'MozTransform',
    O:'OTransform',
    ms:'msTransform',
    standard:'transform'
  }

  for(let key in transformNames){
    if(elementStyle[transformNames[key]] !== undefined){
      return key
    }
  }

  return false
})

export function prefixStyle(style){
  if(vendor===false){
    return false
  }

  if(vendor === 'standard'){
    return style
  }

  return vendor + style.charAt(0).toUpperCase() + style.substr(1)
}